TITLE:   GCN CIRCULAR
NUMBER:  45754
SUBJECT: EP260924a: EP-FXT follow-up observation
DATE:    26/09/26 03:52:54 GMT
FROM:    EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

Y.H. Jiang (NJU), J. P. Chen (SYSU), Y. Q. Zhao (PRIC,USTC), and Y. Liu (NAO,CAS) on behalf of the Einstein Probe (EP) team:
 
We performed a follow-up observation of EP260924a (Jiang et al., GCN 45737). The observation started at 2026-09-25T15:24:01 (UTC, T0+17.5 hours). The effective exposure time of the observation is around 4.9 ks. On-ground analysis of the FXT data found a weak uncatalogued source at R.A. = 339.0218, DEC = 47.0322 (J2000) with an uncertainty of 10 arcsec (radius, 90% C.L. statistical and systematic). The source is faint, and its association with the WXT detection (Jiang et al., GCN 45737) remains uncertain. The average unabsorbed flux is around 7.5e-14 erg/s/cm^2 in the 0.5-10 keV energy band.

No counterparts were detected by WINTER (Mohan et al., GCN 45742). 

Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).